[clang] [clang-format] Finalize children after formatting them (PR #73753)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/73753

This would also fix the overlapping replacements below: $ clang-format
 a(
 #else
 #endif
) = []() {
)}
The new replacement overlaps with an existing replacement. New replacement: <stdin>: 38:+7:"
"
Existing replacement: <stdin>: 38:+7:" "

Fixed #73487.

>From cdeae878936bf32bad612e6a0157280f0f4b9474 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Tue, 28 Nov 2023 22:31:05 -0800
Subject: [PATCH] [clang-format] Finalize children after formatting them

This would also fix the overlapping replacements below:
$ clang-format
 a(
 #else
 #endif
) = []() {
)}
The new replacement overlaps with an existing replacement.
New replacement: <stdin>: 38:+7:"
"
Existing replacement: <stdin>: 38:+7:" "

Fixed #73487.
---
 clang/lib/Format/UnwrappedLineFormatter.cpp | 20 ++++++++++----------
 clang/unittests/Format/FormatTest.cpp       |  7 +++++++
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
index 280485d9a90d1bf..40730cd53529ed3 100644
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -939,6 +939,12 @@ class LineJoiner {
 };
 
 static void markFinalized(FormatToken *Tok) {
+  if (Tok->is(tok::hash) && !Tok->Previous && Tok->Next &&
+      Tok->Next->isOneOf(tok::pp_if, tok::pp_ifdef, tok::pp_ifndef,
+                         tok::pp_elif, tok::pp_elifdef, tok::pp_elifndef,
+                         tok::pp_else, tok::pp_endif)) {
+    Tok = Tok->Next;
+  }
   for (; Tok; Tok = Tok->Next) {
     if (Tok->MacroCtx && Tok->MacroCtx->Role == MR_ExpandedArg) {
       // In the first pass we format all macro arguments in the expanded token
@@ -1060,6 +1066,8 @@ class LineFormatter {
     }
     Penalty +=
         formatLine(*Child, State.Column + 1, /*FirstStartColumn=*/0, DryRun);
+    if (!DryRun)
+      markFinalized(Child->First);
 
     State.Column += 1 + Child->Last->TotalLength;
     return true;
@@ -1429,16 +1437,8 @@ unsigned UnwrappedLineFormatter::format(
       NextLine = Joiner.getNextMergedLine(DryRun, IndentTracker);
       RangeMinLevel = UINT_MAX;
     }
-    if (!DryRun) {
-      auto *Tok = TheLine.First;
-      if (Tok->is(tok::hash) && !Tok->Previous && Tok->Next &&
-          Tok->Next->isOneOf(tok::pp_if, tok::pp_ifdef, tok::pp_ifndef,
-                             tok::pp_elif, tok::pp_elifdef, tok::pp_elifndef,
-                             tok::pp_else, tok::pp_endif)) {
-        Tok = Tok->Next;
-      }
-      markFinalized(Tok);
-    }
+    if (!DryRun)
+      markFinalized(TheLine.First);
   }
   PenaltyCache[CacheKey] = Penalty;
   return Penalty;
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 420afe5992f2a0b..8782cb7c49cad33 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -6361,6 +6361,13 @@ TEST_F(FormatTest, FormatAlignInsidePreprocessorElseBlock) {
                "  int   quux      = 4;\n"
                "}",
                Style);
+  verifyFormat("auto foo = [] { return; };\n"
+               "#if FOO\n"
+               "#else\n"
+               "count = bar;\n"
+               "mbid  = bid;\n"
+               "#endif",
+               Style);
 
   // Test with a mix of #if and #else blocks.
   verifyFormat("void f1() {\n"